Vulnerability in Linux Kernel Affecting AH6 Routing Header Validation

CVE-2026-80844

What is CVE-2026-80844?

CVE-2026-80844 is a vulnerability identified in the Linux kernel that affects the AH6 (Authentication Header for IPv6) routing header validation process. The Linux kernel is the core of many operating systems, providing essential functionality and communication between hardware and software. This particular vulnerability arises when the system improperly handles the "segments_left" value for raw IPv6 HDRINCL packets. Specifically, the assumption that the segments_left value is within expected limits can be violated, leading to an out-of-bounds memory access. This flaw can have severe implications for organizations relying on affected Linux systems, as it opens the door for potential exploitation, impacting system integrity and stability.

Potential impact of CVE-2026-80844

1. Out-of-Bounds Memory Access: The vulnerability may allow attackers to manipulate pointers, leading to out-of-bounds memory accesses. This can potentially cause instability in the system, including crashes or unexpected behavior of critical services.

2. Denial of Service (DoS): Exploiting this vulnerability could enable a remote attacker to crash or hang the affected system, resulting in a Denial of Service. This could severely disrupt organizational operations, especially for those relying on uninterrupted network services.

3. Enhanced Attack Vectors: With an out-of-bounds access, an attacker may find opportunities to leverage this vulnerability to execute arbitrary code or escalate privileges, thereby gaining unauthorized control over the system. This can lead to broader system compromise, data breaches, and further exploitation by advanced persistent threats.

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